If the threshold for hearing increasing 1000 times, the hearing loss is

A decibel is a measure of the ratio between two sound stimuli. The decibel level of a sound that a normal human can hear and is calculated using formula. Intensity (in decibles) $=10 \times \log$ (sound/threshhold) Therefore, the intensity of a sound that is 1000 times, thresh hold is 30 decibels.